When axes are overlapping, LocationEvent.inaxes can point not to the axes we care about, but to another one. Widgets currently recompute location event axes coordinates relative to the axes to which the widget is assigned (#25555), but this recomputation code was previously brittle wrt. events that are outside the axes they wrongly believe they belong to (so x/ydata is None), even though they are indeed within the axes they actually belong to. This can occur when a widget is associated with an "inset_axes" that's actually outside the parent axes. A practical case is given by

frompylabimport*ax=figure(layout="constrained").add_subplot()ax1=ax.inset_axes([0,1,1,.25],sharex=ax)ss=mpl.widgets.SpanSelector(ax1,print,"horizontal")show()# try to trigger the spanselector

which would raise an exception prior to this patch.

Improve the recomputation logic by fully reparenting the event passed to the widget to the correct parent axes from the onset.

PR summary

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